Polymer synthesis and modification

In the late 1970s, Kirchhoff at Dow Chemical Company developed the use of benzocyclobutenes in polymer synthesis and modification. These efforts culminated in 1985 with the issuance of the first patent describing the use of benzocyclobutene in the synthesis of high-molecular-weight polymer.27 Similar work that involved a thermosetting system based on Diels-Alder cycloaddition between terminal benzocyclobutene and alkyne groups,28,29 was reported separately and independently by Tan and Arnold.28 Since these initial discoveries, the field of benzocyclobutene polymers has expanded rapidly and benzocyclobutene chemistry constitutes the basis of a new and versatile approach to the synthesis of high-performance polymers for applications in the electronics and aerospace industries.30... 

Polymer Synthesis and Modification. The condensation reaction between either BTDA or BDSDA and ODA was performed in DMAc at room temperature under a nitrogen atmosphere. ODA (0.004 mole) was added to a nitrogen-purged glass septum bottle with 7 ml DMAc. One of the dianhydrides (0.004 mole) was then added to the diamine solution with an additional milliliter of DMAc resulting in 15-25 wt% solids depending upon the monomer combination. The resulting solution was stirred for 20-24 hours to form the poly(amide acid), a polyimide precursor. For the modified polyimides, anhydrous cobalt(II) chloride (0.001 mole) was added as a solid within one-half hour after the dianhydride. 

Relative to small molecules, the effects of mass transfer on conversion and catalytic constants will be greater for macromolecular substrates. Since diffusion of substrates and products to and from the catalyst will be largely determined by the size of macroporous particles, this variable is particularly important when assessing catalytic supports for enzyme-catalyzed polymer synthesis and modification reactions. To our knowledge, no systematic studies have been reported on how size of macroporous resins influences enzyme activity. 

Industrial irradiation There are 160 gamma-irradiation facilities and over 600 electron-beam facilities in operation in the world. Most facilities are for the sterilization of medical and pharmaceutical products, the preservation of foodstuffs, polymer synthesis and modification, and the eradication of insect infestation. Dose rates in the irradiation chamber would be of the order of 1 Gy s Therefore, there is a need for sophisticated engineered safety systems, and during normal usage the exposure of workers should be very low. The average annual effective dose of 57,200 monitored workers in 15 countries is 0.10 mSv. 

A lot of creative work has been done with transferases, primarily for polymer synthesis and modification reactions. 

The past 15 years have seen great progress in the use of enzymes in organic media to catalyze a wide variety of small molecule transformations. The rationale for using enzymes and its applications as catalysts in polymer synthesis and modification is described elsewhere within comprehensive reviews. ... 

Kobayashi S, Ohmae M (2(X)7) Polymer synthesis and modification by enzymatic catalysis. In Matyjaszewski K, Gnanou Y, Leibler L (eds) Macromolecular engineering precise synthesis, materials properties, applications, vol 10, Wiley-VCH, Weinheim., pp 400-477... 

Cesca, S., Priola, A. and Bruzzone, M. Synthesis and Modification of Polymers Containing a System of Conjugated Double Bonds. Vol. 32, pp. 1—67. 

Synthesis and Modification of New Acrylonitrile Polymers and Copolymers with the Use of Polymer-Analogous Transformations of the Nitrile Groups 115... 

I.4.2.I. Synthesis and Modification of Polymers Unstable bis(nitrile oxide), generated by dichloroglyoxime dehydrochlorination, polymerizes in solution to give poly(furoxan) or (in the presence of 1,3-dienes) gives rise to their being cross-linked (500). Polymerization of terephthalonitrile dioxide and its... 

Important for both the synthesis and modification of polymers is also the elongation of polymer chains. Bisnitrile oxides have been claimed as reagents for chain elongation of polyimides containing terminal groups with C=C, C=C, C=N, C=0, and C=N bonds (504). 

We have already seen in this section how ultrasound, like milling, is capable of producing chain scission and thus give rise to macroradicals. It is therefore not surprising that the application of ultrasound to the synthesis and modification of polymers has attracted, and continues to attract, the attention of many investigators. 

Oxadiazoles and their benzo derivatives find use in applications as diverse as pharmaceuticals, analytical reagents, propellants and explosives, starting materials in organic synthesis, and for polymer preparation and modification. 

Andrianov KA ed. (1976) Synthesis and modification of polymers. Nauka Moscow, pp 5-15, 48-72 c... 

Oxidoreductases comprise a large class of enzymes that catalyze biological oxidation/reduction reactions. Because so many chemical transformation processes involve oxidation/reduction processes, the idea of developing practical applications of oxidoreductase enzymes has been a very attractive, but quite elusive, goal for many years [83], Applications have been sought for the production of pharmaceuticals, synthesis and modification of polymers, and the development of biosensors for a variety of clinical and analytical applications [83], In recent years, the use of oxido-reductive enzymes to catalyze the removal of aromatic compounds from... 

This article surveys the research work on the synthesis and modification reactions of poly(ethyleneimine) as well as its applications to metal complexation processes. Poly-(ethyleneimine), one of the most simple heterochain polymers exists in the form of two different chemical structures one of them is branched, which is a commercially available and the other one linear which is synthesized by cationic polymerization of oxazoline monomers and subsequent hydrolysis of polyf(/V acylimino)cthylcne]. The most salient feature of poly(ethyleneimine) is the simultaneous presence of primary, secondary, and tertiary amino groups in the polymer chain which explains its basic properties and gives access to various modification reactions. A great number of synthetic routes to branched and linear poly(ethyleneimine)s and polymer-analogous reactions are described. In addition, the complexation of polyfethyleneimine) and its derivatives with metal ions is investigated. Homogeneous and heterogeneous metal separation and enrichment processes are reviewed. 

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